| Title: | The Replication Option for Rdb |
| Notice: | Product renamed to Replication Option for Rdb |
| Moderator: | BROKE::PROTEAU |
| Created: | Wed Mar 02 1994 |
| Last Modified: | Wed Jun 04 1997 |
| Last Successful Update: | Fri Jun 06 1997 |
| Number of topics: | 287 |
| Total number of notes: | 1231 |
Hi,
My name is Marcius Machado. I'm working at Digital-Rio.
Here we have a project that has two servers in a hot stand-by
configuration, and we must maintain, at real time, the same information
stored in both servers database, except when one server fails down.
When one server fails down, all information must be stored in the
on-line server, and when the other server gets up, all that information
must be updated in the recovered server database, in less than 3
minutes.
Note that in this case, we can't fix a database as a source
database because we won't be able to know, at every time, what server
will be the on-line server and what server will be the stand-by server.
So, my question is: is it simple to use DDD to implement all those
things, or is it easier to develop that by means of my application ?
If is simple to use DDD for that, could anyone show me how can i do it?
Any help would be appreciated.
Regards,
Marcius Machado
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 286.1 | UKVMS3::PJACKSON | Oracle UK Rdb Support | Fri May 02 1997 11:27 | 6 | |
The Replication Option for Rdb (formally known as DDD) was not designed
for hot stand-by configurations, though it can get fairly warm :-)
You might want to consider using the hot-standby option instead.
Peter
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| 286.2 | Use the Hot Standby Option | BROKE::PROTEAU | Jean-Claude Proteau | Fri May 02 1997 12:57 | 6 |
What Peter says is correct.
Rdb has two methods of replicating an Rdb database: the Hot Standby
Option and the Replication Option. You want the Hot Standby Option in
this case.
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| 286.3 | Two Phase Commit ? | ORAREP::VAXRIO::MARCIUS | Wed May 07 1997 10:42 | 6 | |
Is the Hot Standby Option you are saying the Two Phase Commit Function ?
If it is, i can't use it, because i must be able to store data in one
node, even if the other node is fail down.
Regards,
Marcius Machado
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| 286.4 | NOVA::SMITHI | Don't understate or underestimate Rdb! | Wed May 07 1997 10:56 | 9 | |
~ Is the Hot Standby Option you are saying the Two Phase Commit Function ? No, Hot Standby is a new feature available with Rdb7 as an option. I suggest you investigate it. It allows the Master database to be replicated to a Standby and kept up to date... It can then become the Master when the other database becomes in accessible. The new Master can then be used to refresh the old master later... Ian | |||||
| 286.5 | UKVMS3::PJACKSON | Oracle UK Rdb Support | Wed May 07 1997 11:06 | 18 | |
Hot Standby Option and Two Phase Commit are different things. Hot
Standby is designed for exactly the sort of situation you have
described. Hot standby is new to Rdb7, 2PC has been supported since
V4.0.
Of course if you just want to handle node failures, all you need is a
cluster, and shadowing handles single disk failures.
If you need to be able to continue despite more serious failures, then
hot standby lets you maintain a second copy of the database, which
can be completely up to date if you want. So if your main computer room
burns down, you could switch over to using your standby system, and
start using the standby database immediately. If the standby fails,
then the application would continue on the main database, without the
users noticing.
Peter
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